Lipid class composition as a measure of nutritional condition in individual larval Atlantic cod (Gadus morhua)

Atlantic cod (Gadus morhua) larvae were reared under various feeding environments to assess their lipid class composition and survival during development. Lipids were assessed in individual larvae. Triacylglycerol (TAG), phospholipids (PL), and defatted dry weight (DDW) all fell during yolk absorption. TAG increased after initiation of exogenous feeding in different feeding treatments but did not increase in starved larvae. The percentage of individuals greater than 8 d old with high TAG or PL increased with increasing prey concentration. Survivorship was low in all feeding trials, but groups with a larger percentage of individuals in poor condition tended to exhibit a higher risk of death. We suggest a condition index based on a discriminant function using TAG, PL, and DDW. We assessed the condition of field-collected larvae based on this index.